1. Field
The present application relates to an imaging device.
2. Description of the Related Art
In recent years, video cameras and digital cameras using a CMOS type imaging device are widely used to the public. The CMOS type imaging device includes a pixel array in which plural pixels are disposed in a two-dimensional matrix state. There are a global shutter method simultaneously performing a shutter operation of one screen and a rolling shutter method performing the shutter operation by each selected row as electronic shutter methods for the CMOS type imaging device. In general, it is often the case that the rolling shutter method is used in the CMOS type imaging device (for example, refer to Japanese Unexamined Patent Application Publication No. 2008-288904).
In the rolling shutter method, the shutter operation including, for example, a reset process resetting a pixel before exposure and a read operation reading a signal from the pixel after exposure are sequentially performed by each selected row. Accordingly, for example, the reset process for a last row ends in a middle of a read period from a start of the read operation of a first row to an end of the read operation of the last row. Namely, the reset process of all rows completes in the middle of the read period.
A supply of pulses for the reset process ends in accordance with the completion of the reset process of all rows, and therefore, a power supply voltage varies. Namely, the power supply voltage varies in the middle of the read period in the rolling shutter method. Note that there is a possibility in which the power supply voltage varies when the number of rows of the reset process performed at the same timing changes because the number of pulses changing at the same timing varies. Noise is generated and an image quality deteriorates caused by the power supply voltage variation. For example, the noise generated by the power supply voltage variation generates a horizontal line pattern (electronic shutter defect) at a photographic screen.